Attendees at the California Democratic Convention booed Former Maryland Representative John Delaney (D) after he called the left’s hardline “Medicare for All” stance into question.

Delaney, who was one of the earliest prominent Democrats to throw a hat in the presidential ring, tried to convey his support for universal health care but was brutally booed by attendees after calling for a bit of moderation.

“We should have universal health care, but it shouldn’t be a kind of health care that kicks 150 million Americans off their health care,” he said, sparking a chorus of boos. “That’s not smart policy.”

Former Rep. John Delaney was mercilessly boo’ed during his speech at the California Democratic Convention for his calls for moderation in the party. pic.twitter.com/cGC1PpN8HG

Delaney is not the only Democrat who has dealt with a tough crowd. On Saturday, those attending the California Democrat Convention booed former Colorado Gov. John Hickenlooper (D) after he called the party’s mass embrace of socialism into question.

“If we want to beat Donald Trump and achieve big progressive goals, socialism is not the answer,” Hickenlooper told the crowd.

NBC’s Ali Vitali ‏caught up with former Obama official and current Democrat candidate Julián Castro and asked if Democrat candidates can run a successful primary by taking on more “moderate” positions.

“Oh, you heard the reaction,” Castro said, according to Vitali. “Probably not in this state. Who knows?”

I asked @JulianCastro about candidates – like Delaney and Hickenlooper – who earned boos for speaking against Medicare for All and if you can run in this primary with that stance. “Oh, you heard the reaction,” Castro told me with a laugh. “Probably not in this state. Who knows?”